[Boost-users] Spirit parser - using a skip scanner and file_iterator

From: Phil Endecott (spam_from_boost_users_at_[hidden])
Date: 2005-08-06 12:11:29

Dear Boost Spirit experts,

I've been using Spirit for a few weeks and it is one of the most 
impressive things I've seen for a long time.  Thanks to everyone who has 
made this possible.

Its main problem, as far as I can see, is that the error messages are 
almost entirely incomprehensible.  This is not unusual for C++; the 
compiler (gcc in my case) has a share of the blame too.  The result, in 
my case, is not venturing much beyond the structures used in the 
examples from the (excellent) documentation, and debugging by trial and 
error.

Anyway, I am trying to write a parser that will:
- Use a file_iterator to parse a file.
- Skip comments using #-to-end-of-line syntax.
- Skip whitespace.
- Recognise a simple language.

I can do the main part of the parser (the language); the problem is with 
the comment skipper.  I think that using file_iterator might be making 
it more complicated, though I have also failed to get a char* version to 
compile.

Following the suggestions at 
http://spirit.sourceforge.net/distrib/spirit_1_8_2/libs/spirit/doc/file_iterator.html 
  I have written the following test program:

#include <string>

#include <boost/spirit.hpp>
#include <boost/spirit/actor.hpp>
#include <boost/spirit/iterator/file_iterator.hpp>

using namespace std;
using namespace boost::spirit;

int main(int argc, char* argv[])
{
   string fn = argv[1];

   typedef file_iterator<char> iterator_t;
   typedef scanner<iterator_t> scanner_t;
   typedef rule<scanner_t> rule_t;

   rule_t skip = comment_p("#") | space_p ;
   rule_t language = * ch_p('X') ;

   iterator_t first(fn.c_str());
   if (!first) {
     cout << "Unable to open " << fn << endl;
     exit(1);
   }
   iterator_t last = first.make_end();

   parse_info<iterator_t> info = parse(first, last, language, skip);
}

The errors are attached below.  Can anyone spot what I need to change? 
My feeling is that I need a different type for skip, i.e. not rule_t, 
and I'm pretty sure that I need a definition for scanner_t that mentions 
skip.  I've tried various combinations and got different, equally 
verbose and incomprehensible, error messages.

I'm using Boost 1.32.0 with gcc 3.3.6 on Debian Linux.

Many thanks in advance for any suggestions.

Phil.

$ g++ -Wall -O -o spirit_test spirit_test.cc
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp: In member 
function `
    typename boost::spirit::parser_result<DerivedT, ScannerT>::type
    boost::spirit::impl::rule_base<DerivedT, EmbedT, T0, T1,
    T2>::parse_main(const ScannerT&) const [with ScannerT =
    boost::spirit::scanner<boost::spirit::file_iterator<char,
    boost::spirit::fileiter_impl::std_file_iterator<char> >,
 
boost::spirit::scanner_policies<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int,
    char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>,
    boost::spirit::iteration_policy>, boost::spirit::match_policy,
    boost::spirit::action_policy> >, DerivedT = 
boost::spirit::rule<main(int,
    char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, 
EmbedT =
    const boost::spirit::rule<main(int, char**)::scanner_t,
    boost::spirit::nil_t, boost::spirit::nil_t>&, T0 = main(int,
    char**)::scanner_t, T1 = boost::spirit::nil_t, T2 = 
boost::spirit::nil_t]':
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:171: 
instantiated from `typename boost::spirit::parser_result<DerivedT, 
ScannerT>::type boost::spirit::impl::rule_base<DerivedT, EmbedT, T0, T1, 
T2>::parse(const ScannerT&) const [with ScannerT = 
boost::spirit::scanner<boost::spirit::file_iterator<char, 
boost::spirit::fileiter_impl::std_file_iterator<char> >, 
boost::spirit::scanner_policies<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, 
boost::spirit::iteration_policy>, boost::spirit::match_policy, 
boost::spirit::action_policy> >, DerivedT = 
boost::spirit::rule<main(int, char**)::scanner_t, boost::spirit::nil_t, 
boost::spirit::nil_t>, EmbedT = const boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>&, T0 = 
main(int, char**)::scanner_t, T1 = boost::spirit::nil_t, T2 = 
boost::spirit::nil_t]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:107: 
instantiated from `static boost::spirit::parse_info<IteratorT> 
boost::spirit::impl::phrase_parser<SkipT>::parse(const IteratorT&, const 
IteratorT&, const ParserT&, const SkipT&) [with IteratorT = 
boost::spirit::file_iterator<char, 
boost::spirit::fileiter_impl::std_file_iterator<char> >, ParserT = 
boost::spirit::rule<main(int, char**)::scanner_t, boost::spirit::nil_t, 
boost::spirit::nil_t>, SkipT = boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:154: 
instantiated from `boost::spirit::parse_info<IteratorT> 
boost::spirit::parse(const IteratorT&, const IteratorT&, const 
boost::spirit::parser<DerivedT>&, const boost::spirit::parser<SkipT>&) 
[with IteratorT = main(int, char**)::iterator_t, ParserT = 
boost::spirit::rule<main(int, char**)::scanner_t, boost::spirit::nil_t, 
boost::spirit::nil_t>, SkipT = boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>]'
spirit_test.cc:29:   instantiated from here
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:189: error: no
    matching function for call to `
    boost::spirit::impl::abstract_parser<main(int, char**)::scanner_t,
    boost::spirit::nil_t>::do_parse_virtual(const
    boost::spirit::scanner<boost::spirit::file_iterator<char,
    boost::spirit::fileiter_impl::std_file_iterator<char> >,
 
boost::spirit::scanner_policies<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int,
    char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>,
    boost::spirit::iteration_policy>, boost::spirit::match_policy,
    boost::spirit::action_policy> >&)'
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:213: error: 
candidates   are: typename boost::spirit::match_result<MatchPolicyT, 
T>::type
    boost::spirit::impl::abstract_parser<ScannerT,
    AttrT>::do_parse_virtual(const ScannerT&) const [with ScannerT = 
main(int,
    char**)::scanner_t, AttrT = boost::spirit::nil_t]
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp: In member 
function `
    typename boost::spirit::parser_result<DerivedT, ScannerT>::type
    boost::spirit::impl::rule_base<DerivedT, EmbedT, T0, T1,
    T2>::parse_main(const ScannerT&) const [with ScannerT =
    boost::spirit::scanner<boost::spirit::file_iterator<char,
    boost::spirit::fileiter_impl::std_file_iterator<char> >,
 
boost::spirit::scanner_policies<boost::spirit::no_skipper_iteration_policy<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int,
    char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>,
    boost::spirit::iteration_policy> >, boost::spirit::match_policy,
    boost::spirit::action_policy> >, DerivedT = 
boost::spirit::rule<main(int,
    char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, 
EmbedT =
    const boost::spirit::rule<main(int, char**)::scanner_t,
    boost::spirit::nil_t, boost::spirit::nil_t>&, T0 = main(int,
    char**)::scanner_t, T1 = boost::spirit::nil_t, T2 = 
boost::spirit::nil_t]':
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:171: 
instantiated from `typename boost::spirit::parser_result<DerivedT, 
ScannerT>::type boost::spirit::impl::rule_base<DerivedT, EmbedT, T0, T1, 
T2>::parse(const ScannerT&) const [with ScannerT = 
boost::spirit::scanner<boost::spirit::file_iterator<char, 
boost::spirit::fileiter_impl::std_file_iterator<char> >, 
boost::spirit::scanner_policies<boost::spirit::no_skipper_iteration_policy<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, 
boost::spirit::iteration_policy> >, boost::spirit::match_policy, 
boost::spirit::action_policy> >, DerivedT = 
boost::spirit::rule<main(int, char**)::scanner_t, boost::spirit::nil_t, 
boost::spirit::nil_t>, EmbedT = const boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>&, T0 = 
main(int, char**)::scanner_t, T1 = boost::spirit::nil_t, T2 = 
boost::spirit::nil_t]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:42: 
instantiated from `void boost::spirit::impl::skipper_skip(const ST&, 
const ScannerT&, const boost::spirit::skipper_iteration_policy<BaseT>&) 
[with ST = boost::spirit::rule<main(int, char**)::scanner_t, 
boost::spirit::nil_t, boost::spirit::nil_t>, ScannerT = 
boost::spirit::scanner<boost::spirit::file_iterator<char, 
boost::spirit::fileiter_impl::std_file_iterator<char> >, 
boost::spirit::scanner_policies<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, 
boost::spirit::iteration_policy>, boost::spirit::match_policy, 
boost::spirit::action_policy> >, BaseT = boost::spirit::iteration_policy]'
/usr/include/boost/spirit/core/scanner/skipper.hpp:114:   instantiated 
from `void boost::spirit::skip_parser_iteration_policy<ParserT, 
BaseT>::skip(const ScannerT&) const [with ScannerT = 
boost::spirit::scanner<boost::spirit::file_iterator<char, 
boost::spirit::fileiter_impl::std_file_iterator<char> >, 
boost::spirit::scanner_policies<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, 
boost::spirit::iteration_policy>, boost::spirit::match_policy, 
boost::spirit::action_policy> >, ParserT = boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>, BaseT = 
boost::spirit::iteration_policy]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:108: 
instantiated from `static boost::spirit::parse_info<IteratorT> 
boost::spirit::impl::phrase_parser<SkipT>::parse(const IteratorT&, const 
IteratorT&, const ParserT&, const SkipT&) [with IteratorT = 
boost::spirit::file_iterator<char, 
boost::spirit::fileiter_impl::std_file_iterator<char> >, ParserT = 
boost::spirit::rule<main(int, char**)::scanner_t, boost::spirit::nil_t, 
boost::spirit::nil_t>, SkipT = boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:154: 
instantiated from `boost::spirit::parse_info<IteratorT> 
boost::spirit::parse(const IteratorT&, const IteratorT&, const 
boost::spirit::parser<DerivedT>&, const boost::spirit::parser<SkipT>&) 
[with IteratorT = main(int, char**)::iterator_t, ParserT = 
boost::spirit::rule<main(int, char**)::scanner_t, boost::spirit::nil_t, 
boost::spirit::nil_t>, SkipT = boost::spirit::rule<main(int, 
char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>]'
spirit_test.cc:29:   instantiated from here
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:189: error: no
    matching function for call to `
    boost::spirit::impl::abstract_parser<main(int, char**)::scanner_t,
    boost::spirit::nil_t>::do_parse_virtual(const
    boost::spirit::scanner<boost::spirit::file_iterator<char,
    boost::spirit::fileiter_impl::std_file_iterator<char> >,
 
boost::spirit::scanner_policies<boost::spirit::no_skipper_iteration_policy<boost::spirit::skip_parser_iteration_policy<boost::spirit::rule<main(int,
    char**)::scanner_t, boost::spirit::nil_t, boost::spirit::nil_t>,
    boost::spirit::iteration_policy> >, boost::spirit::match_policy,
    boost::spirit::action_policy> >&)'
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:213: error: 
candidates   are: typename boost::spirit::match_result<MatchPolicyT, 
T>::type
    boost::spirit::impl::abstract_parser<ScannerT,
    AttrT>::do_parse_virtual(const ScannerT&) const [with ScannerT = 
main(int,
    char**)::scanner_t, AttrT = boost::spirit::nil_t]